Holiday Windows Perf Errors

I have 4-20 stamp flats that the long horizontal perf is off as much as 3/8 of an inch. Has any one else come across any of these? I used several of these mailing Christmas cards before I noticed it.
Thanks

Hi, and a very welcome to this forum. Is there any way you can show us a scan? A picture is worth a thousand words...
OK, it just occurs to me that this is a new stamp that does not use perforations but die cuts. Shifted die cuts are not unusual, but I do not know about this particular issue. And by "flats" you must mean a sheetlet?


Peter

Thanks for your reply.
I've collected US stamps and anything to do with the post office since I was 6. I'm almost 70 and am not too familiar with the terms for newer stamps.
I accidentally saw that the sheetlets? (2 3/8" x 5 3/4" with 8 stamps on one side and 12 on the other side)with the shifted die cuts.
With the die cuts off center, it makes the stamp on one side 3/4" and the one on the other side a little over 1 1/2". The shifted die cuts are only on one side of the sheetlet.
It was fun just finding and error or shifted die cut. I had never noticed one before.

David

Nice find. You are not rich, but the are worth a premium and they ad spice to a collection.